Add support for Sourcegraph Amp

[Amp](https://ampcode.com/), an agentic development tool from [Sourcegraph](https://sourcegraph.com/), supports MCP servers, but is not yet supported by ToolHive.

Amp can [be installed](https://ampcode.com/manual?internal#install) as a CLI tool, as well as a plugin for VSCode, VSCode - Insiders, Cursor, and Windsurf. Ideally, it would be nice to support all these configurations.